Halliburton has 90% upside potential over 3 years, says CitiCiti analyst Scott Gruber believes regulatory approval for Halliburton's (HAL) proposed acquisition of Baker Hughes (BHI) is a "high probability event." Halliburton's buyback potential post-acquisition looks significant, Gruber tells investors in a research note. He estimates $5.00 of pro forma earnings per share for Halliburton in 2018, suggesting 90% upside potential for shares over the next three years. The analyst notes that applying a 16 times earnings multiple yields a $78 share price. He keeps a Buy rating on Halliburton with a $54 price target. The oil services company closed yesterday up 75c to $40.74 after reporting Q2 results.